For small cell applications in mobile broadband heterogeneous networks, WiFi—i.e. access via Wireless Local Area Networks (WLANs)—is today considered a key solution. There is currently an intense activity on a global basis on how to integrate WiFi, Worldwide Interoperability for Microwave Access (WiMAX) and CDMA2000 (“Code Division Multiple Access”) with 3rd Generation Partnership Project (3GPP) communication networks in order to offer, in a similar fashion as any 3GPP radio access technology, WiFi integrated with the 3GPP Evolved Packet Core (EPC), i.e. the core network in the Long-Term Evolution (LTE) standard, where the access authentication and authorization is controlled through the network.
Prior art methods exist where the EPC network can be accessed via WiFi, where the WiFi access is authenticated using Subscriber Identity Module (SIM) based authentication methods utilizing for instance Extensible Authentication Protocol (EAP) methods, such as EAP-SIM, EAP-AKA (“Authentication and Key Agreement”) or EAP-AKA', towards the same network entities as are used for 3GPP. For non-SIM Devices such as tablets, laptops, video game consoles, etc., solutions exist where the devices are authenticated through non-SIM based authentication methods, e.g. the well-known EAP-TLS (“Transport Layer Security”), EAP-TTLS (“Tunneled Transport Layer Security”) or Protected Extensible Authentication Protocol (PERP).
Currently, for 2G/3G/4G access, designated entities in the network handles subscription profiles for performing authentication of access to the network. For LTE/4G subscriptions, WiFi or Voice over LTE (VoLTE) access authentication is managed by an entity known as a Home Subscriber Server (HSS).
Authentication of a non-SIM terminal is performed in a 3GPP Authentication, Authorization and Accounting (AAA) server by means of Public Key to Infrastructure (PKI) based authentication methods, such as EAP-TLS/TTLS authentication, and WiFi subscriptions are managed by the HSS similar to the previously mentioned LTE/4G subscriptions, wherein the AAA server downloads required data from the HSS via a 3GPP defined interface referred to as SWx.
In case the non-SIM terminal is associated with an International Mobile Subscriber Identity (IMSI) or virtual IMSI registered with the HSS, the AAA server can download the subscription profile of a user associated with the particular terminal stored in HSS for authentication based on the associated IMSI or virtual IMSI, but the AAA does not need to download an authentication vector comprising required credentials from the HSS.
However, in case no IMSI is associated with the non-SIM terminal, the AAA server cannot download the required user profile/subscription data from the HSS, since the non-SIM terminal has not been registered with the HSS, and the HSS will return an error message to the AAA server. Consequently, the non-SIM terminal cannot be authenticated with the network.